Western snowy plover

Plovers (Charadriidae) are short-billed birds, typically found along open shorelines where they forage on small prey.
A western snowy plover (Charadrius alexandrinus nivosus) may be spotted on a beach hike along the central or southern Californian coast. Their habitat includes beaches, the sand dune hinterland, and—further inland—stream, pond, and lake environments. Natural predators of snowy plovers and their tiny eggs are coyotes, raccoons, and other birds such as falcons and owls. The snowy plover population of the Pacific Coast has been designated a threatened species—not so much because of those predators, but of habitat loss. An interpretive board at a trailhead in the Montaña de Oro State Park, south of Morro Bay and Los Osos, provides the following information:

The coastal strand provides excellent nesting habitat for the threatened western snowy plover. Nests and fledglings are susceptible to loss from human-caused disturbance and predators. Loss of habitat along coastal California has caused concern for the survival of the species.

In the park you'll find certain sand dune areas marked as protected and temporarily closed during the nesting season. Those areas provide spaces wherein the plovers build their nests from kelp, driftwood, shells and whatever else they may find along the shore.

References and resources
[1] California State Parks: Western Snowy Plover • Sharing the Beach
[2] Arcata Fish and Wildlife Office: Western Snowy Plover
[3] Western Snowy Plover • Tools & Resources for Recovery